/*
 * Copyright 2008-2016 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the OpenSSL license (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

#include "aes.h"
#include <string.h>
#if 1
#define STRICT_ALIGNMENT 1
#define OPENSSL_SMALL_FOOTPRINT

unsigned int CRYPTO_cbc128_encrypt(const unsigned char *in, unsigned char *out,
						   size_t len, const void *key,
						   unsigned char ivec[16], block128_f block)
{
	size_t n;
	const unsigned char *iv = ivec;
	unsigned int outLen=0;

#if !defined(OPENSSL_SMALL_FOOTPRINT)
	if (STRICT_ALIGNMENT &&
		((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) {
		while (len >= 16) {
			for (n = 0; n < 16; ++n)
				out[n] = in[n] ^ iv[n];
			(*block) (out, out, key);
			iv = out;
			len -= 16;
			in += 16;
			out += 16;
		 outLen+=16;
		}
	} else {
		while (len >= 16) {
			for (n = 0; n < 16; n += sizeof(size_t))
				*(size_t *)(out + n) =
					*(size_t *)(in + n) ^ *(size_t *)(iv + n);
			(*block) (out, out, key);
			iv = out;
			len -= 16;
			in += 16;
			out += 16;
		 outLen+=16;
		}
	}
#endif
	while (len) {
		for (n = 0; n < 16 && n < len; ++n)
			out[n] = in[n] ^ iv[n];
		for (; n < 16; ++n)
			out[n] = iv[n];
		(*block) (out, out, key);
		iv = out;
	outLen+=16;
		if (len <= 16)
			break;
		len -= 16;
		in += 16;
		out += 16;
	}
	memcpy(ivec, iv, 16);
	return outLen;
}

unsigned int  CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,
						   size_t len, const void *key,
						   unsigned char ivec[16], block128_f block)
{
	size_t n;
	unsigned int outLen=0;

	union {
		size_t t[16 / sizeof(size_t)];
		unsigned char c[16];
	} tmp;

#if !defined(OPENSSL_SMALL_FOOTPRINT)
	if (in != out) {
		const unsigned char *iv = ivec;

		if (STRICT_ALIGNMENT &&
			((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) {
			while (len >= 16) {
				(*block) (in, out, key);
				for (n = 0; n < 16; ++n)
					out[n] ^= iv[n];
				iv = in;
				len -= 16;
				in += 16;
				out += 16;
		   outLen+=16;
			}
		} else if (16 % sizeof(size_t) == 0) { /* always true */
			while (len >= 16) {
				size_t *out_t = (size_t *)out, *iv_t = (size_t *)iv;

				(*block) (in, out, key);
				for (n = 0; n < 16 / sizeof(size_t); n++)
					out_t[n] ^= iv_t[n];
				iv = in;
				len -= 16;
				in += 16;
				out += 16;
		   outLen+=16;
			}
		}
		memcpy(ivec, iv, 16);
	} else {
		if (STRICT_ALIGNMENT &&
			((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) {
			unsigned char c;
			while (len >= 16) {
				(*block) (in, tmp.c, key);
				for (n = 0; n < 16; ++n) {
					c = in[n];
					out[n] = tmp.c[n] ^ ivec[n];
					ivec[n] = c;
				}
				len -= 16;
				in += 16;
				out += 16;
		   outLen+=16;
			}
		} else if (16 % sizeof(size_t) == 0) { /* always true */
			while (len >= 16) {
				size_t c, *out_t = (size_t *)out, *ivec_t = (size_t *)ivec;
				const size_t *in_t = (const size_t *)in;

				(*block) (in, tmp.c, key);
				for (n = 0; n < 16 / sizeof(size_t); n++) {
					c = in_t[n];
					out_t[n] = tmp.t[n] ^ ivec_t[n];
					ivec_t[n] = c;
				}
				len -= 16;
				in += 16;
				out += 16;
		   outLen+=16;
			}
		}
	}
#endif
	while (len) {
		unsigned char c;
		(*block) (in, tmp.c, key);
		for (n = 0; n < 16 && n < len; ++n) {
			c = in[n];
			out[n] = tmp.c[n] ^ ivec[n];
			ivec[n] = c;
		}
	 outLen+=16;
		if (len <= 16) {
			for (; n < 16; ++n)
				ivec[n] = in[n];
			break;
		}
		len -= 16;
		in += 16;
		out += 16;
	}
	return outLen;
}

#endif


#if 0
unsigned int CRYPTO_cbc128_encrypt(const unsigned char *in, unsigned char *out,
						   size_t len, const void *key,
						   unsigned char ivec[16], block128_f block)

{
	size_t n;
	unsigned int outLen=0;
	const unsigned char *iv = ivec;

	if (len == 0)
		return;

	while (len) {
		for (n = 0; n < 16 && n < len; ++n)
			out[n] = in[n] ^ iv[n];
		for (; n < 16; ++n)
			out[n] = iv[n];
		AES_encrypt(out, out, key);
		iv = out;
	  outLen+=16;
		if (len <= 16)
			break;
		len -= 16;
		in += 16;
		out += 16;

	}
	memcpy(ivec, iv, 16);
	return outLen;
}

unsigned int  CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,
						   size_t len, const void *key,
						   unsigned char ivec[16], block128_f block)
{
	size_t n;
	unsigned int outLen=0;
	union {
		size_t t[16 / sizeof(size_t)];
		unsigned char c[16];
	} tmp;

	if (len == 0)
		return;

	while (len) {
		unsigned char c;
		AES_decrypt(in, tmp.c, key);
		for (n = 0; n < 16 && n < len; ++n) {
			c = in[n];
			out[n] = tmp.c[n] ^ ivec[n];
			ivec[n] = c;
		}
	 outLen+=16;
		if (len <= 16) {
			for (; n < 16; ++n)
				ivec[n] = in[n];
			break;
		}
		len -= 16;
		in += 16;
		out += 16;
	}
	return outLen;
}
#endif